:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --bg-color: #8eb6df;
    --card-bg: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --border-color: #cbd5e1;
    --focus-ring: rgba(37, 99, 235, 0.15);
    --error-bg: #fef2f2;
    --error-border: #fecaca;
    --error-text: #991b1b;
}

body {
    font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg-color);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.login-box {
    background: var(--card-bg);
    padding: 36px 32px;
    border-radius: 12px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.05), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    width: 100%;
    max-width: 380px;
    box-sizing: border-box;
    border: 1px solid #e2e8f0;
}

.login-box h1 {
    margin-top: 0;
    margin-bottom: 24px;
    font-size: 22px;
    font-weight: 600;
    text-align: center;
    color: var(--text-main);
    letter-spacing: -0.025em;
}

.login-box .bienvenida {
    text-align: center;
    color: var(--text-muted);
    font-size: 14px;
    margin-bottom: 20px;
}

.login-box input[type="text"],
.login-box input[type="password"] {
    width: 100%;
    padding: 12px 14px;
    margin: 6px 0 16px 0;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    box-sizing: border-box;
    font-size: 14px;
    background-color: #fff;
    transition: all 0.2s ease;
    color: var(--text-main);
}

.login-box input[type="text"]::placeholder,
.login-box input[type="password"]::placeholder {
    color: #94a3b8;
}

.login-box input[type="text"]:focus,
.login-box input[type="password"]:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px var(--focus-ring);
}

.login-box input[type="submit"] {
    width: 100%;
    padding: 12px;
    background: var(--primary-color);
    border: none;
    color: white;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    border-radius: 8px;
    transition: background-color 0.2s ease, transform 0.1s ease;
    margin-top: 4px;
}

.login-box input[type="submit"]:hover {
    background: var(--primary-hover);
}

.login-box input[type="submit"]:active {
    transform: scale(0.99);
}

.login-box .mensaje {
    color: var(--error-text);
    margin: 10px 0;
    text-align: center;
    font-size: 13px;
}

.login-box a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
}

.login-box a:hover {
    text-decoration: underline;
}

.alert-error {
    background-color: var(--error-bg);
    color: var(--error-text);
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 0.85rem;
    border: 1px solid var(--error-border);
    text-align: center;
    font-weight: 500;
}